The present invention relates to ink-jet printing systems, and more particularly, ink-jet printing systems which make use of ink containers that are replaceable separate from a printhead.
Ink-jet printers frequently make use of an ink-jet printhead mounted to a carriage which is moved back and fourth across a print media, such as paper. As the printhead is moved across the print media, a control system activates the printhead to eject or jet ink droplets onto the print media to form images and text.
Previously used printers have made use of an ink container that is separably replaceable from the printhead. When the ink cartridge is exhausted the ink cartridge is removed and replaced with a new ink container. The use of replaceable ink containers that are separate from the printhead allow users to replace the ink container without replacing the printhead. The printhead is then replaced at or near the end of printhead life and not when the ink container is exhausted.
One type of replaceable ink container is disclosed in U.S. Pat. No. 4,558,326 entitled "Purging System for Ink Jet Recording Apparatus" to Kimura et al. discloses the use of a replaceable ink cartridge having a hermetically sealed ink container bag disposed therein. The ink container bag in Kimura is in fluid communication with a recording head. Kimura makes use of the selective application of compressed air to the ink cartridge for pressurizing the ink container bag for forcing ink through the recording head thereby purging bubbles or solid matter from the ink flow path. When the purging of bubbles and solid matter is complete, the source of pressurized air is removed from the cartridge body and the cartridge body is vented to atmospheric pressure. After purging is complete, the recording apparatus in Kimura is operated with the source of pressurized air removed from the cartridge body.
There is an ever present need for ink containment systems that are capable of providing ink at high flow rates to a printhead thereby allowing high throughput printing. This ink supply system should be cost effective to allow relatively low cost per page printing. In addition, the ink supply should be capable of providing ink at high flow rates in a reliable manner to the printhead. An interruption in the flow of ink to the printhead during operation of the printhead can result in excessive heating of the printhead. Operating the printhead without ink can result in catastrophic failure of the printhead or a reduction in printhead life.
Additionally, these ink supplies should be capable of operating over a wide range of environmental conditions, such as atmospheric pressures and changes in atmospheric pressures. These ink supplies should also be transportable over a wide range of environmental conditions without effecting the integrity or reliability of the ink supply. For example, the ink supply should be capable of withstanding rapid changes in atmospheric pressure without a reduction in reliability or reduction in the integrity of the ink container.
Finally, the ink supply should be easily replaceable as well as form reliable fluid connection with the printing device while minimizing or eliminating ink spillage which can reduce the reliability of the printing device.